Thorough and lots of situational questions. Free flowing conversation between the interviewers and me. Asked a the normal questions - why are you looking to leave, what are your goals in your next role etc.

I had 4 interviews with Mercer with 6 employees (4 in Dublin, and 2 in the US). The whole interview process was quite long, it took 6 weeks from the first interview to the offer. The last two interviews were more on chatting instead of proper interviews. The overall experience was quite good.